An Internet Protocol (IP) address in Transport Control Protocol (TCP)/IP widely used for the Internet at present has dual functions, it may serve, in a network layer, as a locator of a network interface of a communication terminal host in network topology, and may serve, in a transport layer, as an identifier of a network interface of a host. Along with the development of a mobile network, when mobile hosts become increasingly popular, defects of the dual functions of such an IP address become increasingly obvious, and directly influence routing extensibility of the Internet and continuity of communication services. An identifier and locator separation technology aims to solve the problem of semantic ambiguity of the IP address. FIG. 1 is a network architecture of a system based on the identifier and locator separation technology in a related technology. A Subscriber Identifier and Locator Separation Network (SILSN) is shown in FIG. 1. In FIG. 1, the SILSN consists of an Access Service Node (ASN), User Equipment (abbreviated as UE, also referred to as Terminal), an Identification and Locator Register (ILR) and the like. The UE accesses the ASN through an access network. The ASN is responsible for accessing the UE to the Internet, and functions in charging, handover and the like. The ILR functions in location registration and query of a user and the like.
In an SILSN, an Access Identification (AID) is taken as an identifier of UE, and a Route Identification (RID) is taken as a locator of the UE, which is actually an identifier of an ASN that the UE accesses, so that each piece of UE accessing the SILSN has its own AID and RID.
When UE accesses an SILSN, its location, i.e. the ASN which the UE accesses, is registered to an ILR through the ASN at first, and the ILR establishes, after the registration of the UE, a corresponding relationship (AID,RID) between an AID of the UE and an RID of the ASN that the UE accesses. If UE1 needs to communicate with UE2, UE1 structures a data message by taking its own identifier AID1 as a source address and taking an identifier of UE2 as a destination address and sends the constructed data message. Afterwards, ASN1 queries a location of UE2, i.e. the ASN (e.g., ASN9 in FIG. 1) which UE2 accesses, to an ILR, then the ASN1 sends the data message to the corresponding ASN9, and the ASN9 processes and sends the message to UE2.
The abovementioned network successfully realizes the separation of an identifier and locator of UE, and the identifier is not required to be changed when a user moves and roams, so that the continuity of a service in a mobile process is ensured. In addition, since routing is implemented in the network according to RIDs of ASNs, and the number of the ASNs is greatly reduced compared with that required when original IP address prefixes are adopted, the routing extensibility of the network is improved.
Along with the enhancement of terminal capability and the development of access technologies, multiple network access manners are gradually utilized at the same time. For example, some terminals may simultaneously adopt a Long-Term Evolution (LTE) manner, a Wireless Local Area Network (WLAN) manner and the like for network access to meet requirements of different scenarios and different services. Under such a condition, a different AID may be allocated to each access manner of each terminal, that is, the same user adopt different user identifiers for access, but by such a method, a user requirement on user identifier uniqueness cannot be met to further meet requirements of network management and Internet services.
The characteristic of user uniqueness may be beneficial to user network security and service application. For example, an Internet management department may conveniently manage, for example, monitor, trace and interrupt, a network behaviour of a user according to a unique identifier of the user, and an Internet service may also acquire service subscription data of the user by virtue of the unique user identifier to realize operation such as single sign-on.
For the abovementioned reasons, it is necessary to improve the SILSN to enable a user to access the network by virtue of a unique user identifier during multiple access and select a proper access manner according to a service characteristic, so as to fully utilize advantages in terms of network security and services brought by use of the unique user identifier in the SILSN to meet a development requirement of a multiple access technology.
FIG. 2 is a diagram of a specific scenario of multiple access in the related technology. As shown in FIG. 2, when a user accesses a network by adopting multiple access manners, in order to keep an AID of the user unique, the AID should be kept unchanged, UE1 accesses different ASNs through different access networks using the same AID, and different ASNs have different RIDs, that is, the same AID may simultaneously correspond to different RIDs. When UE1 receives or sends a data stream, it is necessary to select a proper access manner according to a service characteristic and an access network property, and such a requirement is for an uplink data stream (which is sent to opposite UE by local UE through a network) as well as a downlink data stream (which is sent to the local UE by the opposite UE through the network). For example, for data streams of the same service, the same access manner is generally required to be selected for both uplink and downlink. An access manner for an uplink data stream is generally selected by local UE according to a local strategy or a strategy of the access network, and once an access network is selected, a corresponding ASN is selected. For a downlink data stream, it can be seen from FIG. 2 that the access manner is selected by an opposite ASN, and when the opposite ASN selects a locator of UE, i.e. an ASN which the UE accesses, the access manner is selected. In an example shown in FIG. 2, since the entity for selecting the access manner for uplink data stream is inconsistent with the one for selecting the access manner for downlink data stream, different access manners may be selected for uplink and downlink data streams. How to ensure that proper access manners can be selected for uplink and downlink data streams, especially for the downlink data stream, is a problem required to be emphatically solved in a multiple access scenario.
For the problem of non-uniformity of access manners for uplink and downlink data streams in the related technology, there is yet no solution.